I agree with your point about unsubscribe links, but I don't see how it's not immediately obvious which of your multiple E-Mail addresses you need to unsubscribe with since it's going to be the one the mail was sent to.
For those with vanity URLs and GMail - the trick I use to manage unsubscribes better is to enable 'catch-all address' and registering for new accounts by their URL and TLD, e.g. news_ycombinator_com@URL.com, or kennethcole_com@URL.com, etc.
Two benefits - 1) easier to remember my login per site and 2) if I start getting spammed as a result of my info being shared with third-parties, I can attribute the original offender to the e-mail address.
Also a good way to get vast amounts of dictionary attack spam. One of the mail domains I host was accepting mail to all addresses for some years, and this seems to have attracted even more spam: the volume of junk it gets is disproportionately huge compared to the other similar domains.
My mail server allows -- as an alternative to + so my users can work around braindead address regexes.
You also get few hundred "new viagra price" in your spam folder sent to HjvhBYgVqJ@your.domain. You'll never find kennethcole_com@your.domain in that mess. Even worse is that you get bounced spam emails sent to some@guy.com with from header sent to HjvhBYgVqJ@your.domain and spam filter doesn't see them as spam.
Also, assuming the site isn't brain-dead and invalidating the address, you can use email+site@gmail.com with any gmail or google apps address.
That + is frequently a cause of contention though, so I use a . (which was done via config when I ran my own mail server days gone by) and also have a catchall on google apps.
Gmail accepts multiple forms of email addresses for a single account. first.last@gmail.com is identical to firstlast@gmail.com. I often get subscribed to email lists I don't want using a variant of Gmail address that I never use. Also, plenty of people using forwarding addresses; it may not be clear which address was the target.
What you're saying is odd, because I own a first.last@gmail.com email address and I know the person that owns the equivalent firstlast@gmail.com email address.
Also, the email address to which the message was sent appears clearly in the "To:" header.
Either you or your friend is misspelling their address (more common than you might think, I get opt-in mailing-list mail for myaddress@gmail.com, intended for myaddress@ymail.com), or you've encountered a bug.
You can put periods inside the username part of a gmail address and it still gets through. I'm not sure how what you're saying could be true? Maybe it wasn't always this way.
I thought it was the other way around: mail to firstlast@gmail.com will be delivered to first.last@gmail.com unless firstlast@gmail.com was registered early on.
Google's own google-content-api-for-shopping@googlegroups.com mailing list has this as the "To:" field:
google-content-api-for-shopping@googlegroups.com
And at the bottom of the message:
To unsubscribe from this group, send an empty message.
I had to ctrl-u and check the "Delivered-To:" and "X-Forwarded-For:" headers before I could unsubscribe.
(I'd tried to unsubscribe previously but the subscribed email account forwards to my main account so replying with an empty message didn't work. This thread prompted me to dig a little deeper and finally get one less piece of email per day - thanks HN!)